Solve for $x$ : $4\sqrt{x} - 6 = 9\sqrt{x} + 5$
Answer: Subtract $4\sqrt{x}$ from both sides: $(4\sqrt{x} - 6) - 4\sqrt{x} = (9\sqrt{x} + 5) - 4\sqrt{x}$ $-6 = 5\sqrt{x} + 5$ Subtract $5$ from both sides: $-6 - 5 = (5\sqrt{x} + 5) - 5$ $-11 = 5\sqrt{x}$ Divide both sides by $5$ $\frac{-11}{5} = \frac{5\sqrt{x}}{5}$ Simplify. $-\dfrac{11}{5} = \sqrt{x}$ The principal root of a number cannot be negative. So, there is no solution.